js は現在の日時とその他の操作を取得します。

var myDate = new Date();
myDate.getYear();    //获取当前年份(2位)
myDate.getFullYear();  //获取完整的年份(4位,1970-????)
myDate.getMonth();    //获取当前月份(0-11,0代表1月)
myDate.getDate();    //获取当前日(1-31)
myDate.getDay();     //获取当前星期X(0-6,0代表星期天)
myDate.getTime();    //获取当前时间(从1970.1.1开始的毫秒数)
myDate.getHours();    //获取当前小时数(0-23)
myDate.getMinutes();   //获取当前分钟数(0-59)
myDate.getSeconds();   //获取当前秒数(0-59)
myDate.getMilliseconds();  //获取当前毫秒数(0-999)
myDate.toLocaleDateString();   //获取当前日期
var mytime=myDate.toLocaleTimeString();   //获取当前时间
myDate.toLocaleString( );    //获取日期与时间

Date.prototype.isLeapYear 判断闰年
Date.prototype.Format 日期格式化
Date.prototype.DateAdd 日期计算
Date.prototype.DateDiff 比较日期差
Date.prototype.toString 日期转字符串
Date.prototype.toArray 日期分割为数组
Date.prototype.DatePart 取日期的部分信息
Date.prototype.MaxDayOfDate 取日期所在月的最大天数
Date.prototype.WeekNumOfYear 判断日期所在年的第几周
StringToDate 字符串转日期型
IsValidDate 验证日期有效性
CheckDateTime 完整日期时间检查
daysBetween 日期天数差

// 判断闰年 
//--------------------------------------------------- 
Date.prototype.isLeapYear = function()  
{  
  return (0==this.getYear()%4&&((this.getYear()%100!=0)||(this.getYear()%400==0)));  
}  
 
//--------------------------------------------------- 
// 日期格式化 
// 格式 YYYY/yyyy/YY/yy 表示年份 
// MM/M 月份 
// W/w 星期 
// dd/DD/d/D 日期 
// hh/HH/h/H 时间 
// mm/m 分钟 
// ss/SS/s/S 秒 
//--------------------------------------------------- 
Date.prototype.Format = function(formatStr)  
{  
  var str = formatStr;  
  var Week = ['日','一','二','三','四','五','六']; 
 
  str=str.replace(/yyyy|YYYY/,this.getFullYear());  
  str=str.replace(/yy|YY/,(this.getYear() % 100)>9?(this.getYear() % 100).toString():'0' + (this.getYear() % 100));  
 
  str=str.replace(/MM/,this.getMonth()>9?this.getMonth().toString():'0' + this.getMonth());  
  str=str.replace(/M/g,this.getMonth());  
 
  str=str.replace(/w|W/g,Week[this.getDay()]);  
 
  str=str.replace(/dd|DD/,this.getDate()>9?this.getDate().toString():'0' + this.getDate());  
  str=str.replace(/d|D/g,this.getDate());  
 
  str=str.replace(/hh|HH/,this.getHours()>9?this.getHours().toString():'0' + this.getHours());  
  str=str.replace(/h|H/g,this.getHours());  
  str=str.replace(/mm/,this.getMinutes()>9?this.getMinutes().toString():'0' + this.getMinutes());  
  str=str.replace(/m/g,this.getMinutes());  
 
  str=str.replace(/ss|SS/,this.getSeconds()>9?this.getSeconds().toString():'0' + this.getSeconds());  
  str=str.replace(/s|S/g,this.getSeconds());  
 
  return str;  
}  
 
//+--------------------------------------------------- 
//| 求两个时间的天数差 日期格式为 YYYY-MM-dd  
//+--------------------------------------------------- 
function daysBetween(DateOne,DateTwo) 
{  
  var OneMonth = DateOne.substring(5,DateOne.lastIndexOf ('-')); 
  var OneDay = DateOne.substring(DateOne.length,DateOne.lastIndexOf ('-')+1); 
  var OneYear = DateOne.substring(0,DateOne.indexOf ('-')); 
 
  var TwoMonth = DateTwo.substring(5,DateTwo.lastIndexOf ('-')); 
  var TwoDay = DateTwo.substring(DateTwo.length,DateTwo.lastIndexOf ('-')+1); 
  var TwoYear = DateTwo.substring(0,DateTwo.indexOf ('-')); 
 
  var cha=((Date.parse(OneMonth+'/'+OneDay+'/'+OneYear)- Date.parse(TwoMonth+'/'+TwoDay+'/'+TwoYear))/86400000);  
  return Math.abs(cha); 
} 

//+--------------------------------------------------- 
//| 日期计算 
//+--------------------------------------------------- 
Date.prototype.DateAdd = function(strInterval, Number) {  
  var dtTmp = this; 
  switch (strInterval) {  
    case 's' :return new Date(Date.parse(dtTmp) + (1000 * Number)); 
    case 'n' :return new Date(Date.parse(dtTmp) + (60000 * Number)); 
    case 'h' :return new Date(Date.parse(dtTmp) + (3600000 * Number)); 
    case 'd' :return new Date(Date.parse(dtTmp) + (86400000 * Number)); 
    case 'w' :return new Date(Date.parse(dtTmp) + ((86400000 * 7) * Number)); 
    case 'q' :return new Date(dtTmp.getFullYear(), (dtTmp.getMonth()) + Number*3, dtTmp.getDate(), dtTmp.getHours(), dtTmp.getMinutes(), dtTmp.getSeconds()); 
    case 'm' :return new Date(dtTmp.getFullYear(), (dtTmp.getMonth()) + Number, dtTmp.getDate(), dtTmp.getHours(), dtTmp.getMinutes(), dtTmp.getSeconds()); 
    case 'y' :return new Date((dtTmp.getFullYear() + Number), dtTmp.getMonth(), dtTmp.getDate(), dtTmp.getHours(), dtTmp.getMinutes(), dtTmp.getSeconds()); 
  } 
} 
 
//+--------------------------------------------------- 
//| 比较日期差 dtEnd 格式为日期型或者有效日期格式字符串 
//+--------------------------------------------------- 
Date.prototype.DateDiff = function(strInterval, dtEnd) {  
  var dtStart = this; 
  if (typeof dtEnd == 'string' )//如果是字符串转换为日期型 
  {  
    dtEnd = StringToDate(dtEnd); 
  } 
  switch (strInterval) {  
    case 's' :return parseInt((dtEnd - dtStart) / 1000); 
    case 'n' :return parseInt((dtEnd - dtStart) / 60000); 
    case 'h' :return parseInt((dtEnd - dtStart) / 3600000); 
    case 'd' :return parseInt((dtEnd - dtStart) / 86400000); 
    case 'w' :return parseInt((dtEnd - dtStart) / (86400000 * 7)); 
    case 'm' :return (dtEnd.getMonth()+1)+((dtEnd.getFullYear()-dtStart.getFullYear())*12) - (dtStart.getMonth()+1); 
    case 'y' :return dtEnd.getFullYear() - dtStart.getFullYear(); 
  } 
} 
 
//+--------------------------------------------------- 
//| 日期输出字符串，重载了系统的toString方法 
//+--------------------------------------------------- 
Date.prototype.toString = function(showWeek) 
{  
  var myDate= this; 
  var str = myDate.toLocaleDateString(); 
  if (showWeek) 
  {  
    var Week = ['日','一','二','三','四','五','六']; 
    str += ' 星期' + Week[myDate.getDay()]; 
  } 
  return str; 
} 
 
//+--------------------------------------------------- 
//| 日期合法性验证 
//| 格式为：YYYY-MM-DD或YYYY/MM/DD 
//+--------------------------------------------------- 
function IsValidDate(DateStr)  
{  
  var sDate=DateStr.replace(/(^\s+|\s+$)/g,''); //去两边空格;  
  if(sDate=='') return true;  
  //如果格式满足YYYY-(/)MM-(/)DD或YYYY-(/)M-(/)DD或YYYY-(/)M-(/)D或YYYY-(/)MM-(/)D就替换为''  
  //数据库中，合法日期可以是:YYYY-MM/DD(2003-3/21),数据库会自动转换为YYYY-MM-DD格式  
  var s = sDate.replace(/[\d]{ 4,4 }[\-/]{ 1 }[\d]{ 1,2 }[\-/]{ 1 }[\d]{ 1,2 }/g,'');  
  if (s=='') //说明格式满足YYYY-MM-DD或YYYY-M-DD或YYYY-M-D或YYYY-MM-D  
  {  
    var t=new Date(sDate.replace(/\-/g,'/'));  
    var ar = sDate.split(/[-/:]/);  
    if(ar[0] != t.getYear() || ar[1] != t.getMonth()+1 || ar[2] != t.getDate())  
    {  
      //alert('错误的日期格式！格式为：YYYY-MM-DD或YYYY/MM/DD。注意闰年。');  
      return false;  
    }  
  }  
  else  
  {  
    //alert('错误的日期格式！格式为：YYYY-MM-DD或YYYY/MM/DD。注意闰年。');  
    return false;  
  }  
  return true;  
}  
 
//+--------------------------------------------------- 
//| 日期时间检查 
//| 格式为：YYYY-MM-DD HH:MM:SS 
//+--------------------------------------------------- 
function CheckDateTime(str) 
{  
  var reg = /^(\d+)-(\d{ 1,2 })-(\d{ 1,2 }) (\d{ 1,2 }):(\d{ 1,2 }):(\d{ 1,2 })$/;  
  var r = str.match(reg);  
  if(r==null)return false;  
  r[2]=r[2]-1;  
  var d= new Date(r[1],r[2],r[3],r[4],r[5],r[6]);  
  if(d.getFullYear()!=r[1])return false;  
  if(d.getMonth()!=r[2])return false;  
  if(d.getDate()!=r[3])return false;  
  if(d.getHours()!=r[4])return false;  
  if(d.getMinutes()!=r[5])return false;  
  if(d.getSeconds()!=r[6])return false;  
  return true;  
}  
 
//+--------------------------------------------------- 
//| 把日期分割成数组 
//+--------------------------------------------------- 
Date.prototype.toArray = function() 
{  
  var myDate = this; 
  var myArray = Array(); 
  myArray[0] = myDate.getFullYear(); 
  myArray[1] = myDate.getMonth(); 
  myArray[2] = myDate.getDate(); 
  myArray[3] = myDate.getHours(); 
  myArray[4] = myDate.getMinutes(); 
  myArray[5] = myDate.getSeconds(); 
  return myArray; 
} 
 
//+--------------------------------------------------- 
//| 取得日期数据信息 
//| 参数 interval 表示数据类型 
//| y 年 m月 d日 w星期 ww周 h时 n分 s秒 
//+--------------------------------------------------- 
Date.prototype.DatePart = function(interval) 
{  
  var myDate = this; 
  var partStr=''; 
  var Week = ['日','一','二','三','四','五','六']; 
  switch (interval) 
  {  
    case 'y' :partStr = myDate.getFullYear();break; 
    case 'm' :partStr = myDate.getMonth()+1;break; 
    case 'd' :partStr = myDate.getDate();break; 
    case 'w' :partStr = Week[myDate.getDay()];break; 
    case 'ww' :partStr = myDate.WeekNumOfYear();break; 
    case 'h' :partStr = myDate.getHours();break; 
    case 'n' :partStr = myDate.getMinutes();break; 
    case 's' :partStr = myDate.getSeconds();break; 
  } 
  return partStr; 
} 
 
//+--------------------------------------------------- 
//| 取得当前日期所在月的最大天数 
//+--------------------------------------------------- 
Date.prototype.MaxDayOfDate = function() 
{  
  var myDate = this; 
  var ary = myDate.toArray(); 
  var date1 = (new Date(ary[0],ary[1]+1,1)); 
  var date2 = date1.dateAdd(1,'m',1); 
  var result = dateDiff(date1.Format('yyyy-MM-dd'),date2.Format('yyyy-MM-dd')); 
  return result; 
} 
 
//+--------------------------------------------------- 
//| 取得当前日期所在周是一年中的第几周 
//+--------------------------------------------------- 
Date.prototype.WeekNumOfYear = function() 
{  
  var myDate = this; 
  var ary = myDate.toArray(); 
  var year = ary[0]; 
  var month = ary[1]+1; 
  var day = ary[2]; 
  document.write('< script language=VBScript\> \n'); 
  document.write('myDate = Datue(''+month+'-'+day+'-'+year+'') \n'); 
  document.write('result = DatePart('ww', myDate) \n'); 
  document.write(' \n'); 
  return result; 
} 
 
//+--------------------------------------------------- 
//| 字符串转成日期类型  
//| 格式 MM/dd/YYYY MM-dd-YYYY YYYY/MM/dd YYYY-MM-dd 
//+--------------------------------------------------- 
function StringToDate(DateStr) 
{  
 
  var converted = Date.parse(DateStr); 
  var myDate = new Date(converted); 
  if (isNaN(myDate)) 
  {  
    //var delimCahar = DateStr.indexOf('/')!=-1&#63;'/':'-'; 
    var arys= DateStr.split('-'); 
    myDate = new Date(arys[0],--arys[1],arys[2]); 
  } 
  return myDate; 
} 

function CurentTime()
  { 
    var now = new Date();
   
    var year = now.getFullYear();    //年
    var month = now.getMonth() + 1;   //月
    var day = now.getDate();      //日
   
    var hh = now.getHours();      //时
    var mm = now.getMinutes();     //分
   
    var clock = year + "-";
   
    if(month < 10)
      clock += "0";
   
    clock += month + "-";
   
    if(day < 10)
      clock += "0";
     
    clock += day + " ";
   
    if(hh < 10)
      clock += "0";
     
    clock += hh + ":";
    if (mm < 10) clock += '0'; 
    clock += mm; 
    return(clock); 
  }